//----------------------------------------------------------------------------//
//                                                                            //
// ozz-animation is hosted at http://github.com/guillaumeblanc/ozz-animation  //
// and distributed under the MIT License (MIT).                               //
//                                                                            //
// Copyright (c) Guillaume Blanc                                              //
//                                                                            //
// Permission is hereby granted, free of charge, to any person obtaining a    //
// copy of this software and associated documentation files (the "Software"), //
// to deal in the Software without restriction, including without limitation  //
// the rights to use, copy, modify, merge, publish, distribute, sublicense,   //
// and/or sell copies of the Software, and to permit persons to whom the      //
// Software is furnished to do so, subject to the following conditions:       //
//                                                                            //
// The above copyright notice and this permission notice shall be included in //
// all copies or substantial portions of the Software.                        //
//                                                                            //
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR //
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,   //
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL    //
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER //
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING    //
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER        //
// DEALINGS IN THE SOFTWARE.                                                  //
//                                                                            //
//----------------------------------------------------------------------------//

#include "SkrAnimTool/ozz/additive_animation_builder.h"

#include <cassert>
#include <cstddef>

#include "SkrAnimTool/ozz/raw_animation.h"
#include "SkrAnim/ozz/base/maths/transform.h"

namespace ozz
{
namespace animation
{
namespace offline
{

namespace
{
template <typename _RawTrack, typename _RefType, typename _MakeDelta>
void MakeDelta(const _RawTrack& _src, const _RefType& reference, const _MakeDelta& _make_delta, _RawTrack* _dest)
{
    _dest->reserve(_src.size());

    // Early out if no key.
    if (_src.empty())
    {
        return;
    }

    // Copy animation keys.
    for (size_t i = 0; i < _src.size(); ++i)
    {
        const typename _RawTrack::value_type delta = {
            _src[i].time, _make_delta(reference, _src[i].value)
        };
        _dest->push_back(delta);
    }
}

math::Float3 MakeDeltaTranslation(const math::Float3& _reference,
    const math::Float3& _value)
{
    return _value - _reference;
}

math::Quaternion MakeDeltaRotation(const math::Quaternion& _reference,
    const math::Quaternion& _value)
{
    return Conjugate(_reference) * _value;
}

math::Float3 MakeDeltaScale(const math::Float3& _reference,
    const math::Float3& _value)
{
    return _value / _reference;
}
} // namespace

bool AdditiveAnimationBuilder::operator()(const RawAnimation& _input,
    RawAnimation* _output) const
{
    if (!_output)
    {
        return false;
    }
    // Reset output animation to default.
    *_output = RawAnimation();

    // Validate animation.
    if (!_input.Validate())
    {
        return false;
    }

    // Rebuilds output animation.
    _output->name = _input.name;
    _output->duration = _input.duration;
    _output->tracks.resize(_input.tracks.size());

    for (size_t i = 0; i < _input.tracks.size(); ++i)
    {
        const RawAnimation::JointTrack& track_in = _input.tracks[i];
        RawAnimation::JointTrack& track_out = _output->tracks[i];

        const RawAnimation::JointTrack::Translations& translations =
            track_in.translations;
        const math::Float3 ref_translation =
            translations.size() > 0 ? translations[0].value : math::Float3::zero();

        const RawAnimation::JointTrack::Rotations& rotations = track_in.rotations;
        const math::Quaternion ref_rotation = rotations.size() > 0 ? rotations[0].value : math::Quaternion::identity();

        const RawAnimation::JointTrack::Scales& scales = track_in.scales;
        const math::Float3 ref_scale =
            scales.size() > 0 ? scales[0].value : math::Float3::one();

        MakeDelta(translations, ref_translation, MakeDeltaTranslation, &track_out.translations);
        MakeDelta(rotations, ref_rotation, MakeDeltaRotation, &track_out.rotations);
        MakeDelta(scales, ref_scale, MakeDeltaScale, &track_out.scales);
    }

    // Output animation is always valid though.
    return _output->Validate();
}

bool AdditiveAnimationBuilder::operator()(
    const RawAnimation& _input,
    const span<const math::Transform>& _reference_pose,
    RawAnimation* _output) const
{
    if (!_output)
    {
        return false;
    }

    // Reset output animation to default.
    *_output = RawAnimation();

    // Validate animation.
    if (!_input.Validate())
    {
        return false;
    }

    // The reference pose must have at least the same number of
    // tracks as the raw animation.
    if (_input.num_tracks() > static_cast<int>(_reference_pose.size()))
    {
        return false;
    }

    // Rebuilds output animation.
    _output->name = _input.name;
    _output->duration = _input.duration;
    _output->tracks.resize(_input.tracks.size());

    for (size_t i = 0; i < _input.tracks.size(); ++i)
    {
        MakeDelta(_input.tracks[i].translations, _reference_pose[i].translation, MakeDeltaTranslation, &_output->tracks[i].translations);
        MakeDelta(_input.tracks[i].rotations, _reference_pose[i].rotation, MakeDeltaRotation, &_output->tracks[i].rotations);
        MakeDelta(_input.tracks[i].scales, _reference_pose[i].scale, MakeDeltaScale, &_output->tracks[i].scales);
    }

    // Output animation is always valid though.
    return _output->Validate();
}

} // namespace offline
} // namespace animation
} // namespace ozz
